Embodiments of the invention relate generally to locomotives and other vehicles. More specifically, embodiments of the invention pertain to controlling the movement of locomotives.
When a railcar in a train reaches a destination (e.g., the train might include one or more locomotives and a plurality of railcars), a locomotive operator must stop the locomotive so the railcar is positioned at a predetermined stopping point for unloading the railcar cargo. A locomotive operator can remotely control the movement of the locomotive and railcars via an off-board remote control unit. Such remote control units have an operator interface that enables an operator to transmit commands to an onboard slave control unit that is interfaced with the locomotive onboard operating system. These commands generally relate to locomotive movement parameters such as direction of movement, speed, or braking. The remote control unit communicates with the locomotive operating system and/or slave control unit via a radio frequency (RF) communication system.
However, often times an operator commands the locomotive to move too fast and the locomotive is unable to stop the lead railcar before it passes the predetermined stopping point. As a result, the train may collide with and damage loading docks and nearby equipment, and/or damage the railcar. At present, there is not a method or system that provides the automated speed control and stopping of a locomotive and train, when the locomotive is pushing railcars so a lead railcar is properly positioned at a predetermined stopping point for unloading.
Radio frequency identification (RFID) or automated equipment identification (AEI) tags and readers are used to control movement of trains in rail yards. Specially programmed RFID or AEI tags are sometimes mounted on the tracks between the rails to identify speed limits and stopping points for when the locomotive is pulling cars. The locomotive has an RFID or AEI tag reader installed underneath it to read the tags as it crosses over them. This method of controlling a Remote Control Locomotive movement is not applicable to delivery of railcars to an industry location in which the locomotive is pushing or pulling the cars. Railcars cannot be practically equipped with a RFID reader as it requires a power source and radio for a communication link with the locomotive.
In addition, the tracks at rail yards and other destination locations are often times in very poor condition; therefore, systems having components mounted on the track rails such as impedance circuits may not serve as adequate solutions.